The present invention relates to an apparatus for controlling run of a car, a method of controlling run of a car and a car using the apparatus and, more particularly to following distance controlling auto-cruise including slow acceleration and deceleration running in a congested area. Automatic control technologies are being developed. The automatic control technologies are that a distance between a self-car and a preceding car (including an obstacle) is detected using a radar, and an engine, a motor, a transmission and a brake are automatically controlled so that the distance becomes a safe following distance. An example of the automatic control technologies is following distance controlling auto-cruise including slow acceleration and deceleration running in a congested area (hereinafter, referred to as xe2x80x9cACCxe2x80x9d: Adaptive Cruise Control).
Among the ACC, there are known systems that automatic control is performed only for starting and acceleration operations and a driver operates deceleration and stopping according to his own decision in order to secure higher safety.
One example of the systems is that deceleration and stopping operations and starting and acceleration operations are performed by operating only a brake pedal using a conventional oil brake system.
For example, Japanese Patent Application Laid-Open No.4-38600 discloses a system that when the running mode is set to a slow deceleration running mode due to traffic congestion, the car can be stopped and started by one-pedal running of braking operation. That is, the driving force is controlled so that the running speed of the car becomes a target running speed when there is no brake operation, and the diving force is controlled not to act toward a running direction when there is brake operation.
According to the conventional technologies described above, in order to perform stopping and starting operations by one pedal of braking operation using a conventional brake operating mechanism, the pedal can be used only as if it is an ON-OFF switch, that is, the car is decelerated and stopped when the brake pedal is stepped on, and started and accelerated when the brake pedal is released.
Therefore, in a case of, for example, acceleration a car, the driver is required to be ready to step on the brake operating mechanism so as to rapidly decelerate the car in order to avoid danger, if necessary, while he is releasing his foot from the brake operating mechanism, which is a burden for the driver.
The present invention is characterized by an apparatus for controlling run of a car, the apparatus comprising a pedal for controlling both of a braking force and a driving force of the car depending on an operating amount or an operating force, a footrest function range and a braking force increasing function range being provided in the operating amount or the operating force of the pedal, wherein a footrest function is realized when the operating amount or the operating force of the pedal is within the footrest function range, and run of the car is controlled by a braking force, the braking force being increased corresponding to the operating amount or the operating force of the pedal when the operating amount or the operating force of the pedal is within the braking force increasing function range.
Further, the present invention is characterized by an apparatus for controlling run of a car, the apparatus comprising a pedal for controlling both of a braking force and a driving force of the car depending on an operating amount or an operating force, a footrest function range, a driving force decreasing function range and a braking force increasing function range being provided in the operating amount or the operating force of the pedal, wherein a footrest function is realized when the operating amount or the operating force of the pedal is within the footrest function range, and run of the car is controlled by a driving force, the driving force being decreased corresponding to the operating amount or the operating force of the pedal when the operating amount or the operating force of the pedal is within the driving force decreasing function range; and a braking force, the braking force being increased corresponding to the operating amount or the operating force of the pedal when the operating amount or the operating force of the pedal is within the braking force increasing function range.
Further, the present invention is characterized by that a driving force is generated when the operating amount or the operating force of the pedal is within the footrest function range.
Further, the present invention is characterized by an apparatus for controlling run of a car, the apparatus comprising a pedal for controlling both of a braking force and a driving force of the car depending on an operating amount or an operating force; and a braking mechanism for braking wheels corresponding to the operating amount and the operating force of the pedal, a footrest function range and a braking force increasing function range being provided in the operating amount or the operating force of the pedal, wherein a footrest function is realized when the operating amount or the operating force of the pedal is within the footrest function range, and the braking mechanism is controlled by a braking force, the braking force being increased corresponding to the operating amount or the operating force of the pedal when the operating amount or the operating force of the pedal is within the braking force increasing function range.
Further, the present invention is characterized by an apparatus for controlling run of a car, the apparatus comprising a pedal for controlling both of a braking force and a driving force of the car depending on an operating amount or an operating force; a braking mechanism for braking wheels corresponding to the operating amount and the operating force of the pedal; a following distance detector for detecting a following distance; and a driving force control unit for controlling a driving force corresponding to a signal of the following distance detector, a footrest function range and a driving force decreasing function range being provided in the operating amount or the operating force of the pedal, wherein a footrest function is realized when the operating amount or the operating force of the pedal is within the footrest function range, and the braking mechanism is controlled by a braking force, the braking force being increased corresponding to the operating amount or the operating force of the pedal when the operating amount or the operating force of the pedal is within the braking force increasing function range.
Further, the present invention is characterized by an apparatus for controlling run of a car comprising a first pedal; a second pedal; a footrest apparatus for realizing a footrest function in the first pedal; and a control unit for executing control of a one-pedal mode which controls both of a braking force and a driving force of the car corresponding to an operating amount or an operating force of the first pedal, wherein a means for realizing the footrest function in the footrest apparatus comprises a mechanical stopper mechanism. The mechanical stopper mechanism has an advantage that the footrest apparatus can be constructed with a simple structure even if the other kind of energy such as electric power is difficult to be obtained.
Similarly, a means for realizing the footrest function in the footrest apparatus can be constructed using a solenoid mechanism. By doing so, the holding force can be optimally adjusted by adjusting the electric energy to the load added by a driver""s foot.
Further, a means for realizing the footrest function in the footrest apparatus similarly can be constructed using a combination of springs and cranks. By the means of such a kind, the footrest apparatus can be also constructed without using electric power.
Further, the present invention is characterized by an apparatus for controlling run of a car comprising a first pedal; a second pedal; means for starting and stopping operation of a car power source; and a control unit for selectively executing at least two modes of control of a one-pedal mode and a normal mode, the one-pedal mode control controlling both of a braking force and a driving force of the car corresponding to an operating amount or an operating force of the first pedal, the normal mode control controlling the braking force of the car based on the first pedal and the driving force of the car based on the second pedal, wherein the means for executing starting and stopping of operation of the car power source executes starting of operation of the car power source at the normal mode control. By the apparatus, it is possible to prevent the power source from being operated to start the car when the first pedal is not operated.
Further, the present invention is constructed so that the control unit automatically switches the control from the one-pedal mode control to the normal mode control when operation of the car power source is stopped. By doing so, there is an effect in that since the control unit is in the normal mode operation after stopping operation of the power source, the power source can be started without delay when the power source is restarted.
Further, the present invention is constructed so that the control unit operates the first pedal and executes starting of operation of the car power source at the one-pedal mode control. By doing so, since the power source can be started to be operated while the braking force is added by operating the first pedal even in the one-pedal mode control, the power source can be started to be operated while the car is safely stopped. This method can be applied to idle stop of the power source on an occasion of waiting for traffic signal change, traffic congestion or the like.
Further, the present invention is constructed so that the control unit changes a set acceleration from an acceleration for straight running to another preset acceleration when the car running under the one-pedal mode control on a road in a country or an area where a navigable lane for cars on the road is regulated on the left with respect to traffic flow is turned to the right or turned around the right, or when the car running under the one-pedal mode control on a road in a country or an area where a navigable lane for cars on the road is regulated on the right with respect to traffic flow is turned to the left or turned around the left.
Since the car mounting the apparatus for controlling running in accordance with the present invention is used on an ordinary road, it happens that the car is turned to the right or the left at an intersection or the like. In such a case, when the car is turned to the right in a country such as Japan where the navigable lane is regulated on the left, the car often needs to be speedy turned to the right by passing between cars running on the opposite lane while securing safety. In that case, it is safer to turn to the right if the control unit changes the mode to the preset acceleration for right turning when the car is turned to the right, as in the present invention. On the other hand, when the car is turned to the right in a country or an area where the navigable lane is regulated on the right, it is safer to turn to the left if the control unit changes the mode to the preset acceleration for left turning.
Further, the present invention is constructed so that the control unit changes a set acceleration from an acceleration for straight running to another preset acceleration when the car running under the one-pedal mode control on an ordinary road is turned to the right or turned around the right or when turned to the left or turned around the left. By setting as described above, when the car is turned to the left at an intersection without traffic signals, for example, at an intersection with a stop sign in a country or an area where the navigable lane is regulated on the left, the car often needs to be speedy turned to the right by passing between cars running on the opposite lane while securing safety. In that case, it is safer to turn to the left if the control unit changes the mode to the preset acceleration for left turning when the car is turned to the left, as in the present invention. On the other hand, when the car is turned to the right in a country or an area where the navigable lane is regulated on the right, it is safer to turn to the left if the control unit changes the mode to the preset acceleration for right or left turning.
It is preferable that the timing of the control unit changing the set acceleration is the time when a switch of a blinker is switched on to each of the turning directions. By doing so, the acceleration can be changed only at that time by simple operation of the driver.
Further, in the present invention, in a case where the control unit judges during running that braking operation of the self-car is necessary due to occurrence of some event, the control unit automatically operates a braking mechanism so as to generate a magnitude of deceleration larger than a minimum necessary magnitude of deceleration within a range not affecting health of passengers of the car if a driver does not make any braking operation within a preset time period from occurrence of the judgment. By employing the apparatus for controlling run of a car constructed as described above, if the driver neglects braking operation when the braking operation is required, or if the braking operation is delayed, a warning can be made on the driver by giving a light shock by generating a magnitude of deceleration larger than a minimum necessary magnitude of deceleration within a range not affecting health of the driver. Thereby, the driver will not feel like having such operation of the apparatus any more, and the driver, accordingly, comes to not neglect braking operation. This results in improvement of safety.
Further, the present invention is characterized by an apparatus for controlling run of a car which further comprises a remaining fuel quantity measuring means for measuring a quantity of remaining fuel; and a road inclination measuring means for measuring an inclination of a road based on a difference between a measured result of the remaining fuel quantity measuring means measured at a position of horizontal road and a measured result of the remaining fuel quantity measuring means at present time. Thereby, there is no need to newly add a sensor for measuring inclination by measuring an inclination of a road using a remaining fuel meter attached to any car, which can prevent cost increase. A driving force and a braking force necessary for controlling the car can be calculated using the inclination measured as described above.
Further, the present invention is characterized by an apparatus for controlling run of a car further comprising an inclination measuring means for measuring an inclination of a road; a gear position calculating means for calculating a gear position at braking using an auxiliary baking means based on the inclination of the road measured by the inclination measuring means, and a speed, characteristic data of a power source, a present gear position and an acceleration of the car; and an auxiliary brake braking force calculating means for calculating a braking force by an auxiliary brake means based on a calculated result of the gear position calculating means, wherein when a braking force is generated corresponding to an operating amount or an operating force of the first pedal, a shortage quantity of braking force of only the auxiliary brake means is generated using a main brake means after the time when a target braking force becomes larger than a calculated result of the auxiliary brake braking force calculating means. Thereby, when the driver steps on the first pedal in order to perform braking operation, frequency of using the friction brake can be reduced and accordingly the burden acting on the brake pads can be reduced if the braking force is within a range of the braking force capable of being generated by the engine brake. At the same time, an amount of fuel consumption can be suppressed because fuel is not injected during engine braking.
Further, the present invention is characterized by an apparatus for controlling run of a car further comprising a road inclination measuring means for measuring an inclination of a road; and a braking force holding means for holding a braking force, wherein braking force held at stopping the car is increased larger as an absolute value of the inclination of road is larger when the car is stopped, and the braking force is held by the braking force holding means even if the operating amount or the operating force of the first pedal is decreased until the car is restarted. Thereby, the car can be safely started without moving backward until the car is restarted because the brake oil pressure is maintained when the car is stopped, for example, when the car is stopped on an ascending slope even if the stepping amount of the first pedal is decreased.
Further, the present invention is characterized by that the braking force holding means eliminates the held braking force when a speed-change mode selecting means is changed from a driving mode to a parking mode. Even in a case where the car is stopped on an ascending slope and the braking force is held as described above, if the mode is changed from the driving mode to the parking mode, the car can not be moved backward because the gear is locked. Therefore, in that case, the braking force is released. By doing so, the energy used for the braking can be saved.
Further, the present invention is characterized by that the braking force holding means eliminates the held braking force when a speed-change mode selecting means is changed to a driving mode. When the car is stopped on an ascending slope, it is considered that the car is stopped by using a side brake without setting the parking mode. At that time, the braking force is being maintained during parking. In that case, the car can be safely started by setting the held braking force so as to be released when the mode is changed to the driving mode.
Further, the present invention is characterized by that the speed-change mode selecting means is changed to the driving mode in order to starting the car, a driving force is generated so that the car is moved down backward if it is judged from a measured result of the inclination measuring means that the car is stopped on an ascending road. When the car is stopped on a steep ascending slope and restarted just after releasing the held braking force by loosening stepping of the first pedal, it is considered that the car is sometimes moved backward due to a time lag until the driving force is transmitted, which is dangerous. In that case, if the mode is switched to the driving mode and at the same time the throttle is modified corresponding to the inclination, as in the present invention, the car can safely restarted without being moved backward because a driving force enough to prevent the car from moving backward is generated even if stepping of the pedal is loosened.
Further, the present invention is characterized by the apparatus for controlling run of a car further comprising a friction member temperature measuring means for measuring a temperature of a friction member of a main brake means; and a target braking force modifying means for modifying a target braking force based on the temperature of the friction member measured by the friction member temperature measuring means.
Thereby, the braking force of the main braking means can be appropriately generated based on the temperature of the friction member of the main braking means, and accordingly a stable braking force can be obtained irrespective of the temperature.